How to plan and build a solar park?
Solar energy is now one of the most important sustainable energy sources. No wonder that more and more solar parks are being built. This article shows you how to plan a solar park, how to implement it and how to achieve the best yield from it. But let us briefly show you how it all began.
From the first solar modules to the first solar park
It seems almost impossible to believe, but in fact the so-called photovoltaic effect, which solar systems use today, was discovered as early as 1839 by the French physicist Alexandre Edmond Becquerel. At that time, however, it was not possible to explain why there was an increase in the electrical voltage when irradiated with light. The English electrical engineer Willoughby Smith finally proved the photovoltaic effect on the semiconductor selenium in 1877 and published his research results. In 1883 the first solar module was built by Charles Fritts, a US American. He also used selenium solar cells. However, the efficiency was only 1%. It took more than 20 years before Albert Einstein, the well-known Nobel Prize winner, not only explained the photovoltaic effect with the quantum theory of light in 1905, but also proved it. It took another 40 years to discover the p/n junction in transistors and diodes, so that the development of solar cells based on semiconductors could be further researched. In 1954, 115 years after Becquerel’s discovery, the silicon solar cell was finally invented. At that time, silicon solar cells about 2 cm² in size were used, which were crystalline and still had a very low efficiency of only 6%. Nevertheless, the most important prerequisites were created to make industrial solar cell production possible. Since 1958, photovoltaic energy has been used to supply numerous spacecraft. The first satellite equipped with 108 silicon solar cells, i.e. an entire solar panel, was Vanguard I (USA). The efficiency was already 10%. Since at that time the costs were in no proportion to the benefits, the photovoltaic energy was not yet used on our earth. This happened only after the oil crisis of 1973, which produced numerous research facilities. A number of states financed the order to develop better and above all cheaper solar cells. From around 1975 onwards, more solar cells were produced for use on earth than for space travel. Solar energy became even more important when an incident occurred at the Harrisburg nuclear power plant in the USA in 1979 and the next oil crisis occurred at the same time. Since around 1985, homeowners have been able to install grid-connected photovoltaic systems on their roofs, and more and more solar parks are being built that supply electricity and generate a considerable return for their owners. In the meantime, around 227 gigawatts of PV capacity have been installed worldwide (as of 2015).
The largest solar park in the world is located in China
The Longyangxia solar park is located in the eastern Chinese province of Qinghai on the Tibetan plateau. With a size of 27 square kilometres it can even be seen from space. A total of four million solar modules produce an incredibly large output of 850 megawatts. This makes the Longyangxia solar park currently the largest solar park in the world. It was built in 2013, but it will not be the largest solar park in the world for long, as the next solar park is already being built in the Chinese region of Ningxia, with a capacity of even two gigawatts. China has recognized the signs of the times and has already invested more than 100 billion euros in solar energy.
Why is a solar park or a solar roof system worthwhile for you?
The ever more noticeable climate change is currently causing concern worldwide. Scientists are working flat out to slow climate change, if not stop it, then at least slow it down. A shift from nuclear power and fossil energies to environmentally friendly and sustainable sources such as wind, water or solar energy is urgently needed. Solar energy has the advantage that the sun is always available on a daily basis. Due to climate change, we even get a plus in solar energy in many parts of the world. Solar systems and entire solar parks are therefore becoming increasingly worthwhile.
Who builds a solar park, does thereby not only something good for the environment and improves its ecological footprint clearly, one provides thereby also a quite high net yield. Renewable energies play an ever larger role. And that world-wide. The surfaces, which are needed for solar parks, are however not arbitrarily large. The sooner you invest in a solar park, the higher your chances to get suitable areas, which may even be eligible for EEG funding. Since solar energy will still be needed in decades to come, this is an extremely secure investment that pays off. If you have an area available that can accommodate a solar park or want to purchase one to build a solar park, you should read this article in its entirety. It shows you everything you need to know, from planning to construction to final use.
The decision for a solar park wise make
The decision to build a solar park is of course not made on the side. Here many factors have to be considered and examined. In addition to financial aspects, the existing areas and their suitability also play a major role. And last but not least there is the question whether your planned solar park would be covered by the law for the promotion of renewable energies (EEG). Our competent network will be pleased to assist you with all preliminary considerations, concrete planning and implementation. But first we would like to give you further necessary information to make your decision for a solar park easier.
Is a solar park eligible for subsidies?
A solar park is one of the so-called photovoltaic open space systems. These are very powerful medium-sized to very large photovoltaic systems. Of course such open space plants are also possible in small form on private properties, but here we want to deal rather with solar parks, thus large plants.
In principle it is possible to let your solar park promote after the EEG. However here are some conditions to be fulfilled, which we want to have a closer look at. There are three types of areas for which EEG support is an option. These are:
areas already sealed
conversion areas are areas that were previously used economically or militarily. In most cases, pollutants, explosive ordnance or other problems can be found here which turn the areas into unusable areas. Sealed areas are those which are so heavily sealed by human development that they do not even allow rainwater to penetrate into the soil. As a result, natural processes no longer take place and the area is spoiled for other types of use. As you can see, the eligible areas are usually those that are useless for other meaningful uses. An exception are agricultural areas, which are generally used for the cultivation of food or for animal husbandry. However, solar energy is one of the urgently needed renewable energies, so that the mostly large open spaces in agriculture – if they are no longer needed – are also eligible. This applies to Germany. Please inform yourself in your country about the support possibilities for solar energy.
What else should the area for your solar park be like?
First of all you have to find out whether your area is suitable for the construction of a solar park. In any case, the area should be free of shadows and obstacles such as undergrowth, large stones, trees, etc. If the area is on a slope, the system must be facing south. Furthermore, you must bear in mind that photovoltaic free-standing systems require a permit. They represent a structural measure and are therefore subject to building planning law. The problem here is that each municipality can decide for itself whether a photovoltaic open space system is approved. They have thus no legal requirement on a change of the development plan. If the municipality agrees, it can prescribe concrete conditions for you. For example, this can affect the height of the frames, but it can also happen that you are obliged to carry out a compensatory greening. So having a suitable area does not automatically mean that you can actually build your solar park.
Our tip, if you do not have an area yet:
Always clarify before buying whether you are allowed to use the area as a solar park and whether you will receive all the necessary building permits.
We will of course help you here if necessary. If you wish, we can examine your areas for suitability, clarify the legal issues and then draw up your individual plan for the solar park together with you.
The emergence of a solar park using an example
To plan a solar park is no child’s play. Too many factors play a role here. First of all, it is important to know exactly where your site is located. How often does the sun shine there on average and with what power? Depending on the local conditions, a project drawing will be created. In addition, the electrical data of the future PV system must be determined. Depending on the size of the area, different numbers of PV modules can be installed. The more modules are installed in the solar park, the higher the total output of your PV system. Once this work has been completed, the finished solar park can be projected into it. If everything fits, the final yield calculation takes place so that your investment is secured. No matter how large the solar park is to be, careful planning is immensely important. The PV system must work very reliably over a long period of time. After all, the investment should flow back into your pocket relatively quickly.
As soon as the building permit is available and the grid operator has checked the grid compatibility on site, your solar park can be built. Here, the PV system is first created. The photovoltaic modules of a PV system are mounted on metal frames for this purpose. This ensures optimum alignment and inclination of the solar modules. The racks are usually quite low, but there are also racks that allow agricultural use below the system in parts. The distance between the modules is several metres so that the modules do not shade each other. The direct current generated is converted into the required alternating current on site and immediately fed into the power grid. For this, however, the grid operator must be given more extensive remote control options.
For the PV system, the supports for the support frame are rammed first. It is of great importance to pay attention to a vertical arrangement and the escape. After all, several thousand supports are necessary, depending on the size of the solar park. The trenches for the power lines are then excavated. This is normally done with an excavator. In addition, the cables are laid to the inverter stations. Now the mounting rails, which are essential for the PV modules, can be installed. All this takes about 3 weeks to complete. A good time for interim acceptance. Here the inclination and orientation of your system is checked. Once the entire support structure has been completed, assembly can begin. The PV modules are then electrically connected to each other.
As the inverters require stations, they must be installed in the next step. In addition, the DC and AC sides are connected. Of course, this work is carried out by qualified electricians. One station has about four to six inverters. However, this depends on the wiring. For example, a PV system can have 13 stations with 60 inverters. This is then a decentralised inverter topology. Now your solar park is basically finished. There will be detailed checks of the connections, whereby special measuring instruments will be used. The logging, which takes place here, is extremely important for you. If everything is in order, the cables of the inverter stations can be connected. This works quite simply. They are simply placed on large load-breakers in the low-voltage distribution system. Now they are connected to the transformer (medium voltage) via a so-called busbar system. About 20,000 volts of voltage prevail there. As soon as current flows there, it will amount to about 1,600 amperes at full power.
Now the solar system is completely finished. You can start with the commissioning. For this, however, a detailed inspection of the outdoor area is necessary in advance. During installation, damage can occur in the long rows of modules, especially in larger solar parks. This can be caused by excavation work, but also by stray animals. Such damage can lead to problems as soon as the system is switched on. For this reason, a technician will inspect the outdoor area particularly thoroughly. Another technician will adjust the system according to the grid operator’s specifications. Otherwise the stability of the network is not guaranteed. You must bear in mind that after commissioning, up to 1 megawatt of electrical power is fed into the public grid. If there is an error, this can have fatal consequences. The system is only gradually connected to the public power grid when everything has been completely set up, thoroughly checked and inspected.
The commissioning has long since taken place, when the final acceptance of your system comes. For this purpose, the performance is measured and various safety aspects are checked. With the power measurement it can be determined whether your solar park can produce the yields calculated for you beforehand. The measurements are carried out at full load. They are carried out with the aid of a thermal imaging camera and a characteristic curve measuring device. The data supplied in this way enables the exact creation of a performance picture. In addition, the thermal imaging camera can show possible damage to the PV modules. From time to time transport and assembly can cause such damage that is sometimes not visible with the eyes alone. After all the data has been evaluated, you will receive a system passport. This is the basis for regular maintenance and servicing of the system.
The most important questions about your solar park
What does a solar park cost?
A solar park costs an average of EUR 1,300 per kWp. Around 1% of the investment costs are incurred annually for the operation of the system.
Which modules are best suited for this?
For large-area solar parks, low-cost thin-film modules are used above all.
Are German or Chinese modules better?
As a rule, the Chinese modules are just as good in quality as the German modules. In addition, Chinese manufacturers complete numerous tests and obtain certification. The Chinese modules are popular because they cost up to 20% less. However, there is a clear disadvantage. For example, the photovoltaic installer commissioned is obliged to provide a warranty to his customers for the first two years after installation. If a complaint occurs and he has no Chinese contact, this is not only a problem for the installer. However, there is no big difference in quality.
Which inverters are suitable?
The inverter must be selected according to power, configuration and number of connected modules. Inverters are available from an output of 2 kilowatts and only end in the megawatt range. Whereas previously so-called central inverters were mainly used, string inverters are now also suitable for large plants, preferably in private plants.
What substructure is required?
The substructure is decisive for the stability of your solar system. The solar modules are supported by it and it gives the whole system the necessary stability. The modules are located on the supports and can usually be tilted to make the best possible use of the sunlight. In addition, special loading areas should be part of the substructure so that even strong winds cannot cause any problems. In addition, steel substructures are particularly suitable for a solar park.
Sould tracking systems be used?
Rolling solar systems follow the position of the sun. This allows more yield to be generated. Here there are two possibilities, namely the uniaxial tracking and the biaxial tracking. The uniaxial tracking ensures, depending on the version, that the module field of the sun is horizontal according to the angle of incidence of the sun or vertical according to the solar path. Two-axis tracking offers both options and thus offers the highest yield. Sensor-controlled tracking systems promise optimum yield even under adverse weather conditions. Tracking systems therefore make sense.
Which monitoring systems are there?
Monitoring – Systems inform you about the performance of your plant. Depending on the system and monitoring mode, you will receive data on yields, the amount of your own consumption and the amount of feed-in, among other things. In addition, you can use these systems to draw initial conclusions about the current functionality of the system. If the data deviate from the norm, there is something wrong with the system.
The monitoring systems include completely normal meters, which you read yourself as regularly as possible in order to be able to record the data sensibly. So-called data loggers, i.e. electronic data memories, are more convenient here. They monitor the system completely automatically and record yields and other characteristic values about the performance of the system around the clock. A data logger receives the necessary data from the inverter.
What would the economic efficiency look like in an example?
An annual electricity yield between 400.000 and 500.000 KWh per hectare is the normal case. Up to an output of 10 MW, a feed-in tariff according to the EEG is granted for solar systems. Of course, the plant must be located on an eligible area. Depending on the development, the feed-in tariff is around 10 cents. Thus, the economic use of a solar park is guaranteed in every case. In addition, the prices for modules continue to fall, while electricity prices continue to rise. For this reason, an investment today is very worthwhile even without state subsidies.
Is there anti-theft protection?
There are possibilities to protect your own solar system against theft. These include special screws that have been machined in such a way that they can only be dismantled by drilling them open. In addition, the individual components are equipped with registered and personalized security labels and then registered at www.pv-diebstahl.de In the event of theft, you can quickly track down your property again. Ultimately, most solar park insurers require a secure fence anyway. Camera surveillance and an alarm system are also possibilities that make sense.
How much time passes between planning and commissioning?
Depending on the size of the area, it takes around eight weeks from planning to commissioning. The largest part of the time is spent on official approvals. The construction itself is usually completed within three to four weeks, so that the solar park can then go into operation.
can the electricity produced also be used by the user?
Yes, the electricity produced may in principle be used by the user as required. The electricity not used by the user is then fed into the grid.
Is there a provider who offers all services around solar parks?
Yes, build your solar park with SOLAR.RED! We have a large network at our disposal and are happy to assist you from the idea to commissioning. Today, a solar park is not only a successful investment, but also contributes significantly to environmental protection. Our experienced experts will be happy to advise you on your own project. We support you energetically from the planning to the conversion and if necessary also beyond that with our competent network. Get in touch with us today. We look forward to hearing from you!